What are signs and symptoms of diabetes in cats?

Hello, let me start by explaining my dog died this year from diabetes it was too late before I noticed her symptoms and she was put down to.. I have my cat Spike now and I worry for him (I have bad anxiety), I mean he eats a lot and is kinda chubby he is eight years old nurtured male. He urinates normally and drinks a lot of water, he doesn’t make much bowel movements, but he seems healthy to me. I just don’t want to re live what happened to my dog because my cat is my best friend. What are the chances of him developing diabetes? I had him tested in probably July or September. Negative. But I see him eat 2x a day (when I feed him he eats a little then stops, then comes back in a couple minutes and finishes it until gone, he doesn’t wolf it down right away) and he pees a lot in his litter-box. He also is always playing/splashing in his water dish so I can’t tell if he’s drinking it or just playing in it. I was just hoping for some answers.. I don’t want to run him to the vet every 3 months for a diabetes check if he doesn’t have it.. I just worry for him. Also his coat is clean and nice, not sure on his weight but I will get back with that answer. I would appreciate any suggestions or feedback or experiences with this and how likely is it my cat will develop diabetes.?